My fixed rate mortgage is about to expire! help!?

I have had a fixed rate mortgage for the last two years and its about to expire at the end of march. what do i do next?! will my current lender offer me a new deal or will it change to the standard rate? if i switch will i get charged? any nice websites with advice?! thanks!
Answer
If you are in the uk approach your current lender and ask them if they can re-arrange your mortgage to a better product, if they can offer you one the charge should be minimal, if they cannot shop around and source all lenders, even the internet have some nice offers and the companies use in-house solicitors so fees are still kept low. nice luck.